Miller, originally from North Carolina, was the "grand dragon," or leader, of the Ku Klux Klan there. But when Carolina courts forbid him in the late 1980s from operating a paramilitary guerrilla unit for his stated goal of "establishing a White Southland," Miller skipped out on bond, went underground and ended up in Springfield.

The FBI eventually caught up with Miller, who also goes by Frazier Glenn Cross, in Missouri. He and four other Klansman were tear-gassed out of a mobile home, and law enforcement found a weapons cache: hand grenades, automatic weapons, thousands of rounds of ammunition, C-4 and $14,000 in cash, according to the law center. Miller pleaded guilty to acquiring stolen military weapons and to sending a threat through the mail, which earned him three years in federal prison.

Miller made it back to Missouri in 2002, when he moved to Aurora, outside of Springfield.

By 2004, he was solidly ingrained in the neo-Nazi world, printing the Aryan Alternative, an anti-Semitic, anti-black, anti-basically-everyone newspaper run by prominent Missouri white supremacist Alex Linder of Kirksville. Miller tried to advertise the newspaper in Aurora's weekly shopping guide, with a distribution of about 10,000, but the owners refused to run the ad, according to the U.S. Attorneys Hate Crimes Task Force.

Miller ran failed campaigns for governor and state senator in North Carolina in the 1980s. Earning less than 3 percent of the vote there didn't deter him from running for the legislature once he settled in Missouri. Miller took last place in the 2006 race for Missouri's 7th congressional district with only 23 votes.

Miller tried again in 2010, running for Missouri's seat in the U.S. Senate as a write-in candidate without a specified party. He earned seven votes out of 2 million, according to the Southern Poverty Law Center.

Maybe his 2010 U.S. Senate radio ad had something to do with his defeat:

White men have become the biggest cowards ever to walk the earth. The world has never witnessed such yellow cowards. We've sat back and allowed the Jews to take over our government, our banks, and our media. We've allowed tens of millions of mud people to invade our country, steal our jobs and our women, and destroy our children's futures. America is no longer ours. America belongs to the Jews who rule it and to the mud people who multiply in it.

The Missouri Broadcasters Association and Attorney General Chris Koster complained to the Federal Communications Commission that Miller was not a bona fide candidate, meaning that radio stations shouldn't be required to run his ads.

​"It's a bunch of bureaucratic bullshit," Miller told Daily RFT. "They say I'm not a bona fide candidate because they don't like my message. It's a plot to shut me up and trample my rights to free speech."

In the end, the FCC decided that Miller was not a legitimate candidate and was not eligible for reduced ad rates.

Miller was arrested Sunday on suspicion of shooting and killing three people, including a doctor and his fourteen-year-old grandson, at two Overland Park, Kansas, Jewish community centers just before the Passover holiday.